Jump to content

Recommended Posts

Hey,

 

Having failed to find data like this elsewhere that would actually reflect what I see in game, and in an effort to gather some useable data on level speeds I have made some tests. The intention is not to find out absolute top speeds but top speeds that are close to what one can hope to achieve in combat, and more importantly ones that are comparable to each other to get rough idea on whos how fast at what altitude without frying the engine in a minute. Using 1 min WEP, closing all rads and not caring about overheat, using manual prop pitch in 109 to fry engine even quicker etc. will make one easily surpass these numbers. Test conditions have been as follows within spoilers:

 

Spoiler

-latest version, after radiator boiling effect patch

-Stalingrad Autumn

-Noon, no wind

-full fuel tank, no modifications including ones that alter aerodynamics

-Sustainable radiator positions - minimum 10 min run per plane to validate settings, early on all rads closed to raise temperatures to redline, tested with and without time acceleration

-Radiator positions such that temperatures are high but not quite at the red line to make sure results are repeatable in "real" conditions, lots of engine setting experimenting here

-tests done for maximum continuous power and/or minimum 3 min limited manifold pressure and RPM

-level autopilot, some results validated by flying personally

-always same trim and stabilizer positions used in a plane type and series through altitudes(not necessarily defaults though)

-No 3rd party software used, IAS to TAS conversion made the same way for every test and plane so even if absolute speed numbers are off, relative performance remains comparable

-At 300 m altitude IAS is shown instead of TAS to give reader better understanding on what to expect gauges to read at low altitudes(this is why for example Yak-1 shows 505 at deck instead of 515 written in manual)

 

Please remember that there surely are errors. Repeating this test, you can expect to relatively easily achieve speeds +-2 km/h or so of these. Dont take these results as gospel, they're not, and thats why I dont publish exact IAS and calculated TAS speeds. Not worth it. Interestingly still both combat and emergency power tests for the Fw 190 A-3 are very, very close to real life test data I have found, and a merit to the game and its developers. First, have a look at the fighters that come in Battle of Stalingrad. You are free to use and publish this as it is.

 

1007123661_nopeuksiabos.thumb.png.bd1fdd52a2384d26126b943ef9f1aa26.png

 

Notice especially the LaGG-3 graph. It probably looks like that because it, like the Yak-7, just loves to overheat at middle altitudes and the pilot needs to play with radiator positions and mixture. Right now I have data gathered like this(so they should be comparable) on almost all fighters in the game + some others. Before releasing more results, I need to repeat tests on many plane types as their data is from previous version of the game and likely slightly off at least at high altitudes. I also intend to test at least some of the most popular fighter types at every 500 m or even every 200 m from deck to 7500 m. That will be a big task. Before I publish more I want to hear some of your opinions and thoughts. 

  • Thanks 2
  • Upvote 5
Link to post
Share on other sites
2 hours ago, =EXPEND=Tripwire said:

Thanks very much for taking the time to do this. :good:

 

One request, is it possible to have the graph drawn with altitude on the Y axis, speed on the X so that it looks similar to the speed charts produced in real life? 

 

Its giving me a headache, both OpenOffice Calc and Excel only want to show the values on the Y axis for a line graph. One solution would be to draw the graphs by hand but I dont want to do that just yet, testing and noting down results is enough. :)

Link to post
Share on other sites
35 minutes ago, LeLv76_Erkki said:

 

Its giving me a headache, both OpenOffice Calc and Excel only want to show the values on the Y axis for a line graph. One solution would be to draw the graphs by hand but I dont want to do that just yet, testing and noting down results is enough. :)

 

Use the X-Y format instead of the line graph. Under data ranges you then input lines separately, defining both X and Y every time for each line. 

X and Y Graph.zip

Edited by unreasonable
Link to post
Share on other sites
15 minutes ago, unreasonable said:

 

Use the X-Y format instead of the line graph. Under data ranges you then input line, defining both X and Y every time for each line. 

X and Y Graph.zip

 

Thanks, I didnt realize Excel let one define value axes like that when manually adding value series. I will later today update the graph and add a couple more common planes to it. It gets quite messy and difficult to read with too many of them. For planes with relatively short combat power times like P-40, P-39, La-5 and the 190 I also tested continuous and/or 30 min performance so they have 2 data sets .

Link to post
Share on other sites

flying with closed radiators is also short and used in emergancy and i see for some airplanes you tested them on max with almost fully closed rads, but then some are not shown on their max posible

Edited by 77.CountZero
Link to post
Share on other sites

Hey, yes some planes at some altitudes had closed or nearly closed rads because thats what they can do. In each test I let heat ramp up and then find radiator and mixture settings where it doesnt overheat(5 to 10 degrees below overheat line) and is fastest. I have separate tests for emergency top speeds(P-39 and Fw 190 both really shine at WEP) but they are very much still in the works. Maybe 10 % done. Fw 190 A-3 is here because its full power can be used for 3+ minutes and it has no heat issues at any altitude. Problem with absolute top speeds is that they are difficult and time taking to achieve and can be mainted only for seconds, and how maintainable they are differ very much from plane to plane. Ie. knowing them often has little use in practice. Also in practice after a short fight or climbing, temperatures tend to be already high when WEP is needed and thus when trying to achieve top speeds one is more likely to just cook the engine.

 

Highest sustainable speeds, accounting for both engine modes and heat dissipation, are to me more interesting because they tell more about the performance actually available, as well as speeds and E at the beginning of an engagement. Case P-39: impressive top speed, but in practice it will cruise and fight much slower than 109 or 190. It will use its WEP only to chase someone who is near it's effective gun range and only for very short time, of which it will spend 3/4 of accelerating(and likely overheating too).

Link to post
Share on other sites

Good afternoon, here is revised and more familiar looking graph with some more planes. To demonstrate how much heat and radiator position can effect things I have added La-5's sustainable top speed with boost enabled at 5000 m. It can achieve 600 km/h with oil open, intake open and outlet closed, but to keep temperatures in control it needs 40-50% outlet open and is slowed down all the way to 578-ish km/h. Fortunately for La-5 pilots, when its 15 Celcius at the deck, at and around 5000 m is pretty much the only altitude where the plane has heat issues in level flight. Remember that these values are not exact to 1 km/h accuracy and do not resemble highest possible level speeds that can be achieved - how much higher those are depends on plane, altitude and exact conditions including desired engine life. If these look a bit wonky to you, remember that testing only every 1000 m does give rather poor resolution and that I could not always keep exactly the same temperature reserve so sometimes rads could maybe have been slightly more closed or more open compared to other tests of the same plane. I intend to test at every 500 m in the future..

 

Please look for any mistakes. You are free to use and publish this graph as it is. If you want to know how some specific results were achieved ask here or via PM.

 

nopeuksia1.thumb.png.9d830c87562be614686cbfef36e41b4a.png

 

edit: fixed La-5 unboosted speed at 4000 m. Typo. :)

Edited by LeLv76_Erkki
  • Thanks 2
  • Upvote 2
Link to post
Share on other sites

I thought the resolution in the above previous was unacceptable so I spent yesterday evening and today making some more tests. And revisited some of the previous ones. The Fw 190 A-5 U17+ETC means it has both wing and fuselage bomb racks. Now 500 meter intervals for new planes + for others near their critical altitudes and supercharger stage shift altitudes. Its getting messy, but can see some zig-zag in there already. :) 

 

As before, you are free to use and publish as it is.

 

nopeuksia1.thumb.png.ec5fa1379a5604e6008b66aceea2d042.png

  • Like 2
  • Thanks 3
  • Upvote 3
Link to post
Share on other sites

Great work

 

i see at 7 k, 109 f4 is around 20 kms/h more fast than mig3 ... but seems curve are decreassing for F4 and is hold for Mig3 .  You know values around 9k. I have the impression F4 still more fast at this altitude, than mig3

 

thx.

Link to post
Share on other sites

Done some quick tests on Stalingrad autumn - machines are stock and 100% fuel:

The FW-190-A3 at 3000m at full Emergency: 499km/h IAS

The P-39-L at 3000m at 50-51" MP at 3000rpm: 511km/h* IAS

 

This reflects my experience in the actual combat pre and post patch.

 

EDIT: * - after patch stuff: it seems there is some variable overheating going. 511km/h for the P-39 is at mix 100% and rads are 66/45 (60/45 is the lowest drag setting) to avoid over-heating and the cooling liquid release. Still faster than the A3, thought.

 

Question: does the BoX model the Coriolis force?

Edited by Ehret
Link to post
Share on other sites
1 hour ago, 77.CountZero said:

is this before new patch and new temp calculations ?

 

Hey,

 

All planes except for some low altitude tests for La-5 are from latest patch. Beware there are still inaccuracies(from my flying) and roundings and inevitable errors too. Especially so for planes with water radiators, they can probably squeeze out 1-2 km more without overheating in long runs.

 

@Ehret, in 109 and 190 remember to move the stabilizer ahead. Depending on throttle position it can give you a lot more speed.  Its especially important when speed gap to whatever is chasing you is small.

 

I tested P-39 using auto rich, I need to redo it using full rich even when limiting to 51" Hg and thus 5 min military power. Looks like theres a lot of potential I left unused. Radiators need to be opened somewhat from the flush setting, yes, and it still runs very hot.

Link to post
Share on other sites
1 hour ago, 666GIAP_Tumu said:

Great work

 

i see at 7 k, 109 f4 is around 20 kms/h more fast than mig3 ... but seems curve are decreassing for F4 and is hold for Mig3 .  You know values around 9k. I have the impression F4 still more fast at this altitude, than mig3

 

thx.

 

yes it is faster, and what you see on graph is f4 without max, so its even more faster, G2 is fastest 9-10km, MiG-3 is fast up high for vvs standard but not faster then 109s

  • Upvote 1
Link to post
Share on other sites
13 minutes ago, LeLv76_Erkki said:

I tested P-39 using auto rich, I need to redo it using full rich even when limiting to 51" Hg and thus 5 min military power. Looks like theres a lot of potential I left unused. Radiators need to be opened somewhat from the flush setting, yes, and it still runs very hot.

 

At 3000m altitude at 3000rpm the single gear super-charger will not allow for more than 51". To get faster switch to the manual pitch and keep revs at 3125rpm. (it's still safe)

The 100% mixture degrades engine performance in the P-39, actually, but improves cooling and it's very important to keep P-39' rads as close to the flush setting as possible.

 

Before the patch I could run more like 519km/h as long the timer allowed. Now, there is the pesky overheating it seems... On hotter maps step climbs became problematic as well.

Edited by Ehret
Link to post
Share on other sites

I revisited the P-39. I dont know what had happened there but indeed its much faster when using the 5 min takeoff power(3000 rpm, 51" Hg) setting. Maybe I was looking at 42" line the whole time, like in P-40... I did not adjust propeller pitch manually as I feel its not something that can be done often in practice, as one will be climbing, or diving, or accelerating in combat, and going above 3000 rpm probably reduces the mode timer. Above 3100 or so anyway. How much if any, needs to be tested... These results are purely 3000 rpm, max 51" Hg. I might test manually increased RPM tests later. Until 4500 m radiators need to be opened from flush setting to avoid boiling over and overheating within 5 min. Highest water radiator setting I needed was 74-76 %, but usually much closer to 60 %. The curve actually looks really nice now, just like in the books! :) Continuous power is at 2650 rpm 37" Hg.

 

I'm not sure why 109's curves dont fall back as much as I expected above 6 k. It might be related to cooling, but its real and I tested them several times. What happens at low altitude is almost certainly related to cooling, and maybe the supercharger clutch engaging at 800 m. 109 G-2 only starts falling from 635-ish km/h TAS above 8000 m. Fw 190 tested at stabilizer -90 %, A-5's outlet gills depend on altitude but I was always playing safe. Gills should be safe to close for level speed but in practice A-5's engine will die completely without warning, no technochat either, even when oil inlet temperature gauge shows 40 degrees C, so they were always at minimum 15 % open or halfway between closed and the first white line.

 

Yak-7's supercharger stage switch area isnt very visible, I think its because its more aerodynamic than Yak-1 so S1 and S2 speeds are much closer to each other near 2000 m mark. Need more testing to make the zigzag figure more visible but I dont think its very big.

 

Spoiler

Some Kuban era fighters

nopeuskayra_osa1.thumb.png.e4166c01a9bf53c790740d2903165132.png

 

Edited by LeLv76_Erkki
  • Upvote 1
Link to post
Share on other sites

Notleistung simply means emergency power, they called it Start- und Notleistung(start and emergency power) in early 190s already. C3 and Erhöhte Notleistung are different boost/WEP systems where Notleistung is just the 3 min throttle setting at 1.42 ATA and 2700 RPM. I was thinking of something nice to call the modes, realized they arent called the same in different planes which can be very confusing so I just used mode time limit. I'll change it to 3 min.

  • Upvote 1
Link to post
Share on other sites
  • 4 weeks later...

Hey again,

 

I used the -25 % discount code to get the Spitfire. I have also revisited some planes and found out that for example in LaGG its possible to close the oil rad completely at high altitudes, get more speed and actually not overheat. Upon noticing this I went and tested again most Soviet and Allied planes at every alt. This graph only has a limited number of planes from timeline of 1942 to early 1943 to make it more readable. You can use and share it as it is. Tests done only every 500 meters so you will see inaccuracies near critical altitudes.

 

Spoiler

Il2boxlevelspeeds2.thumb.png.fc3ba2efd523cbbe25fc1e803845b72d.png

 

Edited by LeLv76_Erkki
  • Upvote 1
Link to post
Share on other sites
49 minutes ago, LeLv76_Erkki said:

I used the -25 % discount code to get the Spitfire.

 

The Spit with the mod and the P-39 have very similar cruise speed. If the former stays under 3000m they both are a good fit for a wing-men. I have enjoyed some nice formation flying with Spits when driving Airacobra.

Link to post
Share on other sites
  • 2 months later...
On 11/6/2018 at 4:35 PM, LeLv76_Erkki said:

Hey again,

 

I used the -25 % discount code to get the Spitfire. I have also revisited some planes and found out that for example in LaGG its possible to close the oil rad completely at high altitudes, get more speed and actually not overheat. Upon noticing this I went and tested again most Soviet and Allied planes at every alt. This graph only has a limited number of planes from timeline of 1942 to early 1943 to make it more readable. You can use and share it as it is. Tests done only every 500 meters so you will see inaccuracies near critical altitudes.

 

  Reveal hidden contents

Il2boxlevelspeeds2.thumb.png.fc3ba2efd523cbbe25fc1e803845b72d.png

 

 

was playing with La5 lately and noticed that you get better max speeds if you have sup 2 at 3km on when boost is turned on, but when boost is off you get better speed with sup 1 at that same alt, basicly i got better speeds with sup 1 on up to 5km without using boost, and if i use boost then its better to turn sup 2 from 3km alts, didnt noticed this strange behavior with supercharger and boost on other airplanes, its usealy you have one alt where its best to switch to 2nd sup and nothing els, on La5 it seams if you dont run boost you have one best alt to switch to sup 2 and if you use boost then you have differant best alt to switch to 2nd stage. Will have to see how it works on La5FN.

Edited by 77.CountZero
Link to post
Share on other sites
  • 2 weeks later...
On 2/3/2019 at 11:07 AM, 77.CountZero said:

 

was playing with La5 lately and noticed that you get better max speeds if you have sup 2 at 3km on when boost is turned on, but when boost is off you get better speed with sup 1 at that same alt, basicly i got better speeds with sup 1 on up to 5km without using boost, and if i use boost then its better to turn sup 2 from 3km alts, didnt noticed this strange behavior with supercharger and boost on other airplanes, its usealy you have one alt where its best to switch to 2nd sup and nothing els, on La5 it seams if you dont run boost you have one best alt to switch to sup 2 and if you use boost then you have differant best alt to switch to 2nd stage. Will have to see how it works on La5FN.

 

Yeah it seems to be true, also I think ram air effects the optimal altitude so typically the higher the power setting and speed the higher the switch altitude, in Yaks for example. But that behaviour of La-5 might not be 100 % on ram air.

Link to post
Share on other sites

Recently i retested all fighters (exept 202 and G6 i dont have) in 3.010 and only La5 has this strange differant alt benefit with supercharger and boosted or not boosted.

This is how it lookes for La5 and La5FN for me in top speed tests:

20aw9x0.jpg

 

On La5FN i think combat and emergancy tech chat icon is not corect thats why you see that 2nd line abow 6km (left one is combat and right one is emergancy tech chat ), i see that i can fly long 30min on max power on high alt and techchat say emergancy is active but i dont see timer is counting it down, and its logical that emergancy is not active on FN that high.

Edited by 77.CountZero
Link to post
Share on other sites
  • 2 months later...
On 2/15/2019 at 4:46 PM, 77.CountZero said:

Recently i retested all fighters (exept 202 and G6 i dont have) in 3.010 and only La5 has this strange differant alt benefit with supercharger and boosted or not boosted.

This is how it lookes for La5 and La5FN for me in top speed tests:

20aw9x0.jpg

 

On La5FN i think combat and emergancy tech chat icon is not corect thats why you see that 2nd line abow 6km (left one is combat and right one is emergancy tech chat ), i see that i can fly long 30min on max power on high alt and techchat say emergancy is active but i dont see timer is counting it down, and its logical that emergancy is not active on FN that high.

can i ask you where do you find this chart? i would like to have are look at it if that is posible

Link to post
Share on other sites
1 hour ago, Papa_Bear said:

can i ask you where do you find this chart? i would like to have are look at it if that is posible

its il-2 compare program made for il-2 1946, that i removed data for il-2 1946 airplanes and add data from my speed tests in Il-2 BoX.

Il-2 compare you have here http://www.mission4today.com/index.php?name=Downloads&file=details&id=329

and ill send u in pm my test data that you can just add to original stuff that you can keep or remove and just have il-2 box stuff, i like that program as i can easy see differances.

and you can easy adjust numbers to your test resoults if they are more accurate and so on...

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...